What I don't understand is why is trying to change to a dir in media. Is that you trying to manually change by entering the path?
Shares in ftp are passed to virtual root at this folder /srv, so /media/uuid is never visible.

Can you paste here the contents of this file /etc/proftpd/proftpd.conf

In the field masquerade address put the domain of your house connection the ***.de domain that I see in the connection.

The passive port response is 206x256+191=52927,

I think this is the error, the passive range should be in between 49152-50000 and the server is responding to open different than the ones from the specified. The firewall is opening other ones. This I don't know why is happening.